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authorAndy Lutomirski <luto@amacapital.net>2013-05-13 23:58:40 +0000
committerDave Airlie <airlied@redhat.com>2013-05-31 13:02:52 +1000
commitd0d98eedee2178c803dd824bb09f52b0e2ac1811 (patch)
tree302ece15c574dc061b1dea4e67125c7b01342154 /arch/x86/include/asm/mtrr.h
parente81f3d81e282a156b47c1c2c09a1976e34073060 (diff)
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Add arch_phys_wc_{add, del} to manipulate WC MTRRs if needed
Several drivers currently use mtrr_add through various #ifdef guards and/or drm wrappers. The vast majority of them want to add WC MTRRs on x86 systems and don't actually need the MTRR if PAT (i.e. ioremap_wc, etc) are working. arch_phys_wc_add and arch_phys_wc_del are new functions, available on all architectures and configurations, that add WC MTRRs on x86 if needed (and handle errors) and do nothing at all otherwise. They're also easier to use than mtrr_add and mtrr_del, so the call sites can be simplified. As an added benefit, this will avoid wasting MTRRs and possibly warning pointlessly on PAT-supporting systems. Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/mtrr.h')
-rw-r--r--arch/x86/include/asm/mtrr.h10
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86/include/asm/mtrr.h b/arch/x86/include/asm/mtrr.h
index e235582..f768f62 100644
--- a/arch/x86/include/asm/mtrr.h
+++ b/arch/x86/include/asm/mtrr.h
@@ -26,7 +26,10 @@
#include <uapi/asm/mtrr.h>
-/* The following functions are for use by other drivers */
+/*
+ * The following functions are for use by other drivers that cannot use
+ * arch_phys_wc_add and arch_phys_wc_del.
+ */
# ifdef CONFIG_MTRR
extern u8 mtrr_type_lookup(u64 addr, u64 end);
extern void mtrr_save_fixed_ranges(void *);
@@ -45,6 +48,7 @@ extern void mtrr_aps_init(void);
extern void mtrr_bp_restore(void);
extern int mtrr_trim_uncached_memory(unsigned long end_pfn);
extern int amd_special_default_mtrr(void);
+extern int phys_wc_to_mtrr_index(int handle);
# else
static inline u8 mtrr_type_lookup(u64 addr, u64 end)
{
@@ -80,6 +84,10 @@ static inline int mtrr_trim_uncached_memory(unsigned long end_pfn)
static inline void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)
{
}
+static inline int phys_wc_to_mtrr_index(int handle)
+{
+ return -1;
+}
#define mtrr_ap_init() do {} while (0)
#define mtrr_bp_init() do {} while (0)
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